ANDROID
When calls fail or mobile data stops working, the cause is often a setting, a weak signal or a SIM that is not seated or active. Google's Pixel Phone Help page on mobile connectivity lists the checks in a sensible order. This guide goes through the mobile data and SIM parts.
Before you start: Google's page is written for Pixel phones. Menu names on other Android phones differ, so use these steps as a guide. Google also describes call and mobile data diagnostics, but says that feature is available only in the US for US subscribers on Pixel 11 phones, so most people will use the manual checks below.
Step 1: Check mobile data settings
- Open Settings.
- Tap Network & Internet, then SIMs.
- Make sure Mobile data is on.
- Tap your carrier's name and make sure Use SIM is on.
Also check airplane mode. In Settings, tap Network & Internet and turn airplane mode off.
Step 2: Check the network type
In Settings, tap Network & Internet, then SIMs, then your carrier, and look at the preferred network type. Google lists 5G (recommended), 2G, 3G and LTE, depending on what your carrier offers, and says the options can vary by country. Google adds that when 5G is not available, Pixel phones with 5G fall back to 4G and lower networks.
Step 3: Check signal strength
To be sure you are on the mobile network, turn Wi-Fi off first: Settings, Network & Internet, Internet, then switch Wi-Fi off. Google says the triangle icon at the top right shows signal strength, and the more filled it is, the stronger the signal. With little or no signal, try moving to another location, or ask your carrier about coverage in your area.
Step 4: If 5G feels slow
- Google says a 5G icon only shows that 5G service is available in the area. It does not mean your phone is getting 5G at that moment.
- Turn off Battery Saver. Google says Battery Saver turns off 5G.
- Some carriers offer 5G in smaller areas than their other service, and different carrier networks offer different kinds of 5G with different speeds. Ask your carrier about its coverage and speeds.
- Google says not all Pixel 4a (5G) and later phones work on all 5G networks, so check with your carrier that your model works on its 5G network.
Step 5: Check the SIM
Go to Settings, Network & Internet, SIMs, and select your carrier. If you have a SIM but it is inactive, turn on Use SIM. Google says that if your carrier name is gray with the message "No SIM," you either have no SIM or it is inactive. If you do not have a SIM activated yet, you can insert a physical SIM or download one, depending on your carrier.
To check a physical SIM:
- Push a SIM ejection tool or small paperclip into the hole in the SIM tray until the tray pops out.
- Take out the SIM card and look at it.
- If it is damaged or bent, contact your carrier for a replacement. If it has dirt or dust, wipe it with a microfiber cloth.
- Put the clean, intact SIM back in.
If the problem continues and you have another SIM, try it in your Pixel. Google also suggests putting your SIM in another phone to see whether the SIM itself is the problem.
eSIM notes
Google says you can transfer an eSIM from Settings under Network & internet, SIMs, Add SIM, Transfer SIM from another device. If a transfer fails, try again, and contact your carrier if it keeps failing. Google also says Pixel 8 and later phones on Wi-Fi can convert a physical SIM to an eSIM, after which the physical SIM no longer works, so confirm the eSIM works before you throw the old card away.
Wi-Fi calling
Google says not all carriers support Wi-Fi calling, so check with yours. To change it, go to Settings, Network & Internet, SIMs, then Wi-Fi calling, turn Use Wi-Fi calling on or off and place a test call.
Source: Google, "Fix mobile connectivity issues", Pixel Phone Help, https://support.google.com/pixelphone/answer/14116080 (read November 13, 2026). If these steps do not fix it, contact your carrier.